Model Fifteen speaker impedance?

[Chris1this1]

I just picked up a Model 15 turntable/amp unit, unfortunately sans speakers. My research shows a ported dual 4” driver design for the speakers, but no luck finding the info of system impedance. Would like to harness the maximum power output of this thing by using the proper impedance speakers, so that is the question. Thanks! 

[JKent]

Here's a handy reference: http://www.aphenos.net/electronics/speakers/klh/all_klh.htm

The Fifteen, 14B and 19 were all the same. Two of the ubiquitous "Twelve point five" drivers with a port (!!). I've worked on a few but unfortunately I have no pics of the innerds and no notes. Here's a shot I pulled off the interweb. Pretty sure there's a filter network. The 2 drivers are each 8 ohms, wired in series.

Kent

[RoyC]

8 hours ago, JKent said:

Here's a handy reference: http://www.aphenos.net/electronics/speakers/klh/all_klh.htm

The Fifteen, 14B and 19 were all the same. Two of the ubiquitous "Twelve point five" drivers with a port (!!). I've worked on a few but unfortunately I have no pics of the innerds and no notes. Here's a shot I pulled off the interweb. Pretty sure there's a filter network. The 2 drivers are each 8 ohms, wired in series.

Kent

Kent,

If these are 8 ohm drivers, and the charts in your link are correct, they are wired in parallel not in series. Your photo appears to have them wired in a parallel arrangement as well.

Roy

[JKent]

Oops. Thanks. I was thinking of the dual 3" Model Eight speakers I’ve been working on. It's been a whole since I worked on the 14, 15, 19 but I should have realized: The impedance of the series-wired dual driver early Eights is about 15 ohms so I should have known parallel would have made the speakers 4 ohms. Senility? Mad cow disease? Sorry Chris.